This is a phase II randomized multicenter double blind trial of two doses of SC 49483 in combination with zidovudine (ZDV) versus ZDV in subjects with HIV-1 infection, CD4 cell counts of 150-350 cells/mm3 and no more than 12 months ZDV monotherapy or combination therapy with DDL or DDC. Subjects are stratified by prior ZDV therapy and viral phenotype (SI versus NSI) the NNSI stratum closed 2-13-95. UCHSC is no loner participating in this trial effective July 95 and no patients were enrolled.